Rotary-retort furnace.



PATENTED AUG. 11, 1908.

J. R. MOFFITT. ROTARY RETORT FURNACE.

APPLIUATION FILED JAN. 16, 1906.

' wif/mwoco 7 SHEETS-$HEET 1 PATENTED AUG. 11, 1908.

J. R. MOPFITT. ROTARY RETORT FURNACE.

APPLICATION FILED JAN.16, 1906.

7 SHEBTS-SHEBT 2.

No. 895,656. PATENTED AUG.11, 1908.

J. R. MOFFITT.

ROTARY RETORT FURNACE.

APPLICATION FILED JAN.16, 1900.

'7 SHBET k-SHEET 3.

PATENTED'AUG. 11, 1908. J. R. MOFJEITT.

ROTARY RETORT FURNACE.

APPLICATION FILED JAN. 16, 1906.

7 SHEETS-SHEET 4.

J. R. MOFFITT.

PATENTED AUG. 11, 1908.

-ROTARY B-ETORT FURNACE.

APPLICATION IILED JAN. 16, 1906.

'7 SHEETS-SHEET 5.

[LIL

No. 895,656. PATENTED AUG. 11, 1908. J. R. MOFFITT.

ROTARY RETORT FURNACE.

A PPLIOATION FILED JAN.16,190G.

7 SHEETS-SHEET 6.

No. 895,656. PATENTED AUG. 11, 1908. J. R. MOFPITT.

ROTARY RETORT FURNACE.

APPLICATION FILED .TAN.16, 1906.

7 SHEETS-SHEET 7.

U'Nrrni) s'rArEs PATENT ent ies.

JOHN R. MOFFITT, OF DENVER, COLORADO.

. what I term a rotary retort furnace.

ROTARY-RETORT FURNACE.

No. 895,656. g

' Specification of Letters Patent.

Patented Aug. 11, '1908.

Application filed January 16, 1906. Serial No. 296,389.

'To all whom it may concern:

Be it known that I, JOHN R. MoFrrrT, a citizen of the United States, residing in the city and county of Denver-and State of U010- rado, have invented certain new and useful Improvements in Rotary-Retort Furnaces; anr I do declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being bad to the accompanying drawings, and to the letters and figures of reference marked thereon, which form a part of this specification.

My invention relates to improven'ients in This construction includes as shown in the drawing, a cylindrical retort mounted to rotate in the COlIlbLLStiOIl chamber ofthe furnace, the retort, however, being shut off from the products 'of combustion which circulate around the furnace, the heat within the retort being communicated to the material 'undor treatment by radiation. This retort is provided interiorly with a number of longitudinally disposed rabble troughs adapted to carry up the ore from the lower part of the retort and drop it downwardly when the trough has assumed the emptying or inverted position, the pulverized ore being in this manner advantageously subjected to themtion of the heat within the retort. Provision is made for introducing atmospheric air '(either hot or cold) under pressure, directly to the ore within the longitudinal rabble troughs. These troughs are so constructed that the air is introduced into a chamber adj acent the ore-holding portion of the trough, provision being made for allowing the air to escape in limited volume into the trough. By virtue of the retarding means employed between the trough and the air chamber, the

Provision is therefore made for cutting. off

the air supply from the troughs on the downwardly moving side of the rotary retort. This is a-eeomplisl'ied through the instrumentality of a valve or cutoff adapted to be eadily actuated from the outside of the furnace. Provision is also made for carrying off the volatile products or fumes from the retort, and introducing them into a body of liquid whereby the fumes are condensed and their values saved. Another important result of this introduction of the fumes to the liquid body is that certain volatile impurities which are poisonous and injurious to life, are also condensed thus relieving the atmos here in the vicinity of the furnace from t 1e deadly fumes ordinarily attending the use of constructions of this class.

This furnace performs the roasting or oxidizing function in a most thorough and ellicient manner and as heretofore indicated makes provision for saving all of the volatile values or those which would ordinarily pass off with the fumes.

Having briefly outlined my improved construction as well as the function it is intended to perform, 1 will proceed to describe the same in detail reference being made to the accompanying drawing, in which is illustrated an embodiment thereof.

In this drawing, Figure 1 is what 1 will term a rear view of my improved apparatus since it illustrates the discharge extremity of the furnace. Fig. 2 is a side elevation of the same. Fig. 3 is a front end elevation of the furnace. Fig. 4 1s a section taken. on the line 4---4 Fig. 2 viewed in the direction of the arrow. Fig. 5 is a' vertical longitudinal section of the furnace. Fig. (3 is a cross section taken on the line 6 6 Fig. Fig. 7 is a detail view showing a conduit and a perforated hood employed for introducing the fumes to the body of liquid for purposes of condensation. Fig. 8 is a fragmentary top view of the perforated head. Fig. 5) is a sectional view of the same. Fig. 1() is across section of one of the troughs. Fig. 1 l is an enlarged detail view of the air chamber from which the air is distributed to the various "troughs. In this view the rear plate of the vhamber is removed,- thus disclosing the valve or cut-off. The wall of the casing is also shown partially in section.

The same referencecharacters indicate the same parts in all the views.

Let the numeral 5 designate the combustion chamber of my improved furnace which as shown in the drawing is composed of double walls with a filling (S of asbestos or other suitable non-combustible substance which is also a poor conductor of heat. This fire box is provided with a bottom 7 and a grate S below which is the bottom by a movable plate controlled by a crank 12 having a socket 13 for the insertion of a handle 14 for operating urposes. Below the ash pit, the base of the 'urnace is provided with a water rece tacle 15 into which the ash from the as pit may be dropped. The furnace may also be cooled bottom of t e box, first into the ash it and then into the liquid receptacle 15. e members of the grate 8 are actuated from the outside of the furnace by two meshing oii by droplpinfgl'r the burnin fuel from the segmental gears 16 which are engaged by ---norma lly closed by some suitable trans ent and non-combustible material 22 w pivoted dogs 17 and 18, the distancebetween the cogs of the gear being sufficient to allow a limited shaking movement of. the grate bars without disengaging the ogs. Each gear is provided with a socket 19 ada ted to receive an operating handle 20 ibr o crating purposes. If it is desired to dump t e entire contents of the firebox into the ash pit, the dogs 17 and 18 will be thrown out 'of engagement with the gears inwhich event, by a roper movement of the handle 20 the grate Ears may be thrown downwardly in which event the entire cbntents of the fire box will be precipitated into the ash pit. The fire box is supplied with fuel through side 0 enings 21 normally closed by doors 22 hinged at 23and provided with peep holes arich' has suitablyconnected thereto the bar 22 for o ening and closing the same.

. Within the combustion chamber above the bottom thereof, is mounted a revoluble retort 22. This retort, at the forward extremity of the furnace is journaled upon a conduit 23 containing a-feed screw 24 to.

which the'material to be treated is fed from a hopper 25. The outer extremity of the feed screw shaft is provided with an operating pulley 26. The inner extremity of the feed screw casing is provided with a hinged closure 25 the same being hinged at the top and adapted to open asv the ore is crowde rearwardly by the feed screw. The rear extremity of the retort is journaled in a housing 27 located at the rear extremity of the furnace and into which the retort protrudes. This housing chambercommunicates at the top with two fume conducting conduits 28 which extend upwardly and then downwardly telescoping in a member 29 provided at its lower extremity witha hood 30 which is open at the bottom but provided with perforated upper walls 31, these perforations being formed by punching whereby the metal forced out of the openings is ushed inwardly forming a rough and agger inner surface for the hood. This roug and jagged surface together with the perforations, erforms an important function in the con ensation of the fumes since these fumes are theash pit 9 closed at v separated, strained and disintegrated so to speak, whereb 7 they issue from the hood by a great number of pass ages which facilitates the distribution of the fumes through the body of liquid and causes thorough condensation. This liquid may be water or any. other liquid compound or substance which may be found necessary in order to condense the valuable and poisonous fumes. 1

"To the forward'end of the retort immediately in the rear of the door 25 of the feed screw casing, provided with openings into which are duits 34 terminating in members 35 con nected with the forward extremities of the rabble troughs 36 mounted near the inner wall of the furnace and longitudinally disposed therein. The troughs are supported at their forward extremities by tubular members 35 which ass through ,apertured lugs 44 formed on a g wall of the retort. the troughs are provided with projections'4 6 which pass through aper'tured lugs 47 mounted on a band 48 secured to the inner wall of the retort. Furthermore the series of is located an air chamber'32 screwed nozzles 33 communicating with conand 45 secured to the inner The rear extremities of troughs is connected together by a polygonal shaped ring or band composed of a series of members 49 secured to each other and to the band by means of bolts 42 which pass through the troughs and are secured by nuts '43. These troughs as shown in the drawing are composed of two members 37 and 38 inclosing an air chamber 39 and an ore receptacle 40. The two members are connected by bolts, 11 and fiirther by the bolts 42 which connect the troughs with the polygonal ring as heretofore explained. The airchamber 39 is cylindrical in shape and has an opening 50 communicating .with

( isposed member 51 cylindrica section.

of arms 51 which hold'the air chamber sus pended. With this chamber is connected thefomvard extremity of a conduit 52 which is longitudinally disposed and whose axis 00- incides with the axis of the retort. This conduit protrudes from the retort at its rear ex tremity and engages a bearing 53 attached to the rear wall of the housing 47; This hearing is provided with a packing 54 of asbestos or other suitable material forming an air tight joint around the conduit. The housing or rear extremity of the outer wall of the furnace is provided with an opening which is entered by a stationary inlet 55, communicating with an air pipe 56 in whichis located the ore receptacle 410 by s aces on opposite sides of a lon itudinally in cross Through the instrumentality of this device-the escape of air from the chama controlling valve 57. The rear extremity of the inlet 35 is closed at the rear as shown at 58 and through this closure passes a rod 59 provided with an exposed member 60. The rod 59 forms the stem of a valve 61 located in the air chamber, the valve being of the same shape as the exposed member 60. This valve is of suflicient size to close the orifices of the air chamber communicating with a number of conduits 34. As heretofore intimated it is not necessary that air should be delivered to the troughs of the retort except when the troughs contain ore. Therefore the valve is of sufficient size to close the ori-' r fices leading to the troughs on the downwardly moving side of the retort.

To the rear extremity of the rotary retort is attached a discharge member 62 provided with spirally arranged ribs of blades 63, to facilitate the discharge of the roasted ore, into the housing 27 whence it passes into a casing 64 provided with a screw conveyor 65 having a pulley 66" at one extremity. This suitable power for the purpose of pulley may be connected with any suitable power for operating the discharge conveyor.

The rear extremity of the furnace or the rear wall of the housing 27 is provided with openings closed by doors 66 mounted to swing on rods 67. These doors are locked in place by latches 68. They are also provided with peep holes 69 preferably covered by some transparent material, a metal plate 70 beingemployed to protect the transparent device from the outside, except when it is necessary to view the interior operations of the'furnace,

The fume conduits 28 are provided with dampers 71 operated by levers 72 fulcrumed as shown at 73.

As shown in the drawing there are two liquid-containing tanks 74 in which the hoods 30 with the fume conduits arc innncrsed. Between. these liquid-containing tanks 74, is located a hood .75 directly above an opening 76 communicating with the combustion chamber and located at the top thereof, for

the escape of the products of combustion which as heretofore explained do not come in contact with the material under treatment. This hood communicates at its upper extremity with a stack 7.6 into which may be introduced a jet pi pc 77 through which air or steam undcr pressure may be passed to increase 'the draft of the furnace. Attention is called to thefact that the ro tary retort protrudes from the rear extremity of the combustion chamber and projects into the hood' 27. Between the combustion chamber and the hood 27, the rotary retort is provided with a sprocket gear 78 connected with a smallersprocket wheel 7 9 by means of a chain 80. The sprocket 79 is fast on a shaft 81 which may be connected with any imparting the rotary movement to the retort.

Between the combustion chamber and the rear housing 27, the wall of the furnace is provided with wheels or anli-frictional bearings 82 which engage the retort extcriorly for supporting and centering purposes.

At the rear extremity of the combustion chamber, the latter is provided with a ring 83 which engages a similar ring 84 fast on the exterior wall of the retort. Between these rings is interposed a packing S5 of some suitable non-combustible material as asbestos, in order to form an air tight joint where the retort passes out of the combustion chamber.

. From the foregoing description the use and operation of my in'iproved furnace will be un-- derstood. Assuming that there is a fire on the grate and the furnace is suitably heated, the ore to be treated is fed into the retort from the hopper 25 through the instrumentality of the screw conveyor 24-. The retort is of course rotated and as the troughs move upwardly on one side thereof, they carry the ulverized ore with them, the same having been dipped from the lower part of the retort 'into which it is continually falling as it is fed into the rear extremity thereof. It must be understood that the retort as well as the entire structure is slightly inclined downwardly from its forward to its rear extremity where by there is a tendency of the ore cntcringthc forward extremity of the retort to move rcar wardly or into the paths of the troughs. As these troughs are carried upwardly being filled with ore as ind' rated in Fig. 6, air is introduced under pressure from the air chamber 32-as heretofore explained. lndcr the inilucnceof the heat of the furnace and the oxygen of the air, the ore is thoroughly roasi5- ed and deprived of its volatile impurities, which pass off in fumes, the fumes being carried into the hood 27 and thence through the conduits 28 into the liquid-containing tanks.

74 where they are condensed as heretofore explained. As the troughs move downwardly on the downwardly moving side of the retort, they discharge their contents downwardly through the heated air of the furnace whereby the ore is adwintagcously exposed to the action of the heat. ator takes care to adjust the valve (Si in operating its stem through the instrumentality of the exposed controlling device, so that the air will not enter the troughs on the downwardly moving side of the retort. The exposed member of the valve stem 52) occupics the same position on the stem as the valve 61. Hence the operator always knows the position of the valve by looking at the member 60.

As the air is carried up by the rabble troughs on the upwardly moving side of the retort and falls downwardly on the opposite side, it is being gradually worked rearwnrdly toward the discharge end of the retort which it finally reaches and is delivered to the hood The opcrl -which nuts E are applied housing 27.

by the spirally ribbed member 62. After entering the hood it reaches the screw conveyer discharged'from the furnace.

65 and IS I The fume conduit 28 is rovided at its lower extremity with a col ar B which is somewhat curved on its lower surface and engages the correspondingly curved seat G formed on an upward extension A of the As shown in the drawing (see Fig. 7)..the conduit 28 is composed of two members having flanges C connected by) the to upper threaded extremities of rods above and below. The lower extremities of these rods are hooked into eyes F'formed on the housing 27 Now if it is desired to move the hood 30 farther outwardlyor toward the left referring to I Fig. 7, without plunging the hood deeper in the li uid, this may be done by adjusting the nuts on the rods D in such a manner as to raise the flanges C on one side of the conduit and lower these flanges on the other side of the conduit whereby the hood is tilted, and

. the collar B shifted on 1ts seat accordingly.

Through the instrumentality of conduits 2 projecting into the ash pit 9, air under pressure may be delivered to the grate and caused to pass upwardly into the fire box to aid combustion.

I claim is: I

1. In apparatus of the class described, the combinatlon with a combustion chamber, of a retort mounted to rotate therein but cut off from communication therewith, rabble troughs mounted in the retort'and rotating therewith and connected together by a series of members forming a polygonal shaped ring or band, each trough being provided with an air'chamber and an ore receptacle communicating therewith, and means forintroducing air under pressure to the air chambers, said means comprising an air chamber carried by the retort and communicating with the individual air chambers of the respective rabble troughs.

2. In apparatus of the class described, the combination with a combustion chamber, of

, a retort mounted to rotate therein and proyided with rabble troughs, each trough havmg an air chamber and an orereceptacle, the

' two chambers beingin communication with each other, and means for introducing air under pressure to ,the individual air chambers of the troughs comprising a common air chamber carried by the retort and communic'ating with the individual air chambers of the respective rabble troughs, a valve located in the common air chamber and adjustable from the outside of the furnace for cutting off the air chamber from the rabble troughs while moving through a predetermined arc of their travel.

3. In apparatus of the class described, the

combination with the combustion chamber,

Having thus described 'my invention, what.

ofa retort mounted to rotate therein and whose interior is out OK from communication with the combustion chamber, rabble troughs mounted in the retort to rotate therewithand connected together by a series of members forming a polygonal shaped ring or band, each provided with an air receptacle and an air chamber communicating therewith, and means for introducing air under pressure to the air chambers of the rabble troughs, and means for cutting ofithe' air from the rabble troughs on the downwardly moving side of the retort. I

4. In a construction of the class described, the combination with a combustion chamber, of 'a retort mounted to rotate therein but having no communication therewith, longitudinally disposed rabble troughs located 111 the retort an connected together by a series of members forming a polygonal shaped ring or band, means for feeding to the retort the material to be treated, and means for -.intro-.

ducing air under pressure rabble troughs. v

5. In a construction of the class described,

to the individual of a retort mounted to rotate therein but having no communication therewith, rabble troughs located in the to ether by a series of members forming a o ygonal shaped ring or band, means for ceding to sure to the individual rabble troughs comrising a common air chamber, and conduits eading therefrom to therespective troughs. 6. In a construction of the class described, the combination with a combustion chamber, of aretort mounted to rotate therein but having no communication therewith, rabble troughs located in the retort and connected to ether by a series of members forming a polygonal shaped ringor band, means [for eeding to the retort the material to be treat-' ed, meansfor introducing air under presspre 4 the combination with a combustion chamber,

retort and connected the retort the material to be treat- 'ed', and means for introducing air under presto the individual rabble troughs comprising a common air chamber and conduits leadin respective troughs, an means for cutting off the air from the troughs therefrom to the chamber, of a rotary retort located therein the retort,

or cutting 0d the air while passing through ain and connected to rotate with the retort and whose axis coincides with the axis of the retort, a centrally disposed conduit located in the retort and connected with the air chamber to deliver air thereto, an external connection for delivering air to the conduit under pressure, and conduits leading from the air chamber to the respective rabble troughs.

9. The combination with a combustion chamber, of a retort mounted to rotate therein and provided with rabble troughs located therein and rotating therewith and connected to ether by a series of members forming a po ygonal shaped ring or band, an air chamer, conduits leading from the air chamber to the respective rabble trou hs, a conduit connected with'the air chamber and also rotating with the retort, the axis of the conduit coinciding with the axis of the retort, and exterior means for delivering air under pressure to the last named conduit. 10. The combination with a combustion chamber, of a retort mounted to rotate therein, and rabble troughs carried by the retort and rotating therewith and connected together by a series of members forming a pol yg-.

onal shaped ring or band, a casing mounted at one extremity of the combustion chamber, protruding into the retort and forming a bearmg for one end of the latter, a screw conveyer located in the said casing for delivering the material to be treated to the retort, rabble troughs located in the combustion chamber, an air chamber located directly in the rear of the feed conveyer, conduits leading from the air chamber'to the respective rabble troughs, and means for introducing air under pressure to the air chamber.

11. The combination with a combustion chamber, of a retort mounted to rotate in the combustion chamber, rabble troughs ca ried by the retort, an air chamber mounted to rotate with the retort, conduits leading from the air chamber to the respective rabble troughs, a valve located in the air chamber, a stem connected with the valve and disposed in axial alinement with the retort, and protruding therefrom, its outer extremity having a member shaped and disposed to correspondwith the shape and position of the valve.

12. The combination with a combustion chamber, of a retort revqluble therein, a feed pipe mounted.at one extremity of the com- )ustion chamber, provided with a hinged closure, said pi e protruding into the retort and forming a caring for the letter at one end, a screw conveyor located in the feed pipe, a housing open to receive the rear extremity of the retort beyond the combustion chamber and forming an exterior bearing for the retort, sullicient space between the housing and the chamber to allow power means to be applied to said retort, and a conveyer located at the bottom of the housing and protruding therefrom to discharge the treated material after it leaves the retort.

13. The combination with a combustion chamber, of a retort mounted to rotate therein and cut off from communication therewith, a housing located at the rear extremity of the combustion chamber into which housing the retort protrudes, its protrudin extremity being open to communicate wit the housing, sufficient space between-the housing and chamber to allow ower means to be aplied to said retort, a iquid-containing tank ocated outside of the combustion chamber, and a conduit leading from the combustion chamber and provided with a relatively large hood immersed in the liquid and )erforated at the top for the escape of the lumes into the liquid. i

14. The combination with a combustion chamber, a retort mounted to rotate therein, a feed pipe located at one extremity of the combustion chamber, protruding into the retort and forming a bearing therefor at one extremity of the combustion chamber, a housing located at the opposite extremity of the retort beyond the combustion chamber, the retort protruding into the housing and open to communicate therewith, a gear surrounding the retort between the combustion chamber and the housing, and means connected with the gear for rotating the retort. In testimony whereofatlix my signature in presence of two witnesses.

JOHN R. HOFFI'IT.

\Nitnesses DENA NELSON, A. J. OBRIEN. 

